Self-sensing dispensing device

ABSTRACT

The present self-sensing dispensing device includes: power supply means, a liquid dispensing element comprising an actuator and a dispensing aperture through which liquid is to be dispensed by activation of the actuator, electronic control means operable to control the actuator, liquid supply means connecting with a liquid reservoir to supply liquid to the liquid dispensing element, valving means allowing or blocking liquid to flow from the reservoir to the liquid dispensing element, wherein the actuator operates to execute in itself at least a dispensing function and a detecting function, the detecting function detecting at least characteristics external to the self-sensing dispensing device and causing the actuator to generate a command signal, and wherein the electronic control means is operable to control the valving means and the actuator based on the reception of the command signal.

This application claims priority from European Patent Application No. 09152 483.5, filed Feb. 10, 2009, the entire disclosure of which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a self-sensing dispensing device,suitable for dispensing liquid substances, such as by activating a flowor a spray of droplets. Such device normally contains a dispensing bodyon a support part, in particular, a spout or a nozzle body of a liquiddroplet spray device that dispenses a liquid substance from the devicethrough the dispensing body. Such activation may be carried out byvalving means to allow a flow and/or by pumping or pressurizing means.Such activation may further be carried out by a piezoelectric actuatorused as a vibrating element for causing the liquid to vibrate so to beaccelerated and expelled. A typical device further may consist ofelements such as a liquid space, liquid feed and fluid interface to areservoir, a reservoir as well as electrical connections between thevibrating element and a corresponding electronic circuitry. The liquidmay be for example an ambient fragrance, a perfume, an insecticide, afungicide, a fabric softener, an aromatherapy essence, a cleaningsolution, a liquid pharmaceutical formulation, a lotion, cream,emulsion, aqueous based liquids and flammable or combustible liquids.

Such dispensing bodies are sometimes called spouts, aperture plates,nozzle arrays, dosing apertures, orifice plates, vibratable membranes,atomizer, vibrating plate, dosing aperture arrangements, aerosolgenerators and the like. Such terms are hence to be understood as beinginterchangeable throughout the present document.

BACKGROUND OF THE INVENTION

In fact such dispensing bodies and liquid dispensing devices are wellknown. For example, see the document EP 1 129 741, in the name of thepresent Applicant. This document describes a dispensing device forspraying liquid and has a top substrate formed of a main body and of anozzle body. The nozzle body contains a nozzle array of liquid dropletoutlet means allowing a liquid substance contained in the liquid dropletspray device to exit the device, in this case as a spray of droplets. Apiezoelectric actuator is used to cause the liquid to undergo avibration so as to generate the droplet spray.

Generally, such piezoelectric actuator is driven so as to oscillate ator near an appropriate frequency to improve energy efficiency.

The document EP 1 043 162 describes an inkjet apparatus having a liquiddetection method using an infrared detector to determine if liquid haspassed through a spray path or not. Control means are provided to adjustthe spraying itself.

The document US 2007/0216256 describes a drive control circuit for apiezoelectric activated pump. By measuring the internal impedance of thepiezoelectric actuator, it is possible to control the operationfrequency.

Document US2003/0146300 describes a nebulizer for nebulizing a substanceand a reservoir having a metering chamber arranged so as to feed asubstance to be nebulized from the nebulization device and a secondchamber arranged to hold and retain any of this substance in excess ofthe volume held in the metering chamber. The device allows detecting theejection of a unit dose.

However, a simplified and reliable controlled activation anddeactivation of the actuator would be useful if the actuator couldfunction by itself so as also to detect dispensing conditions and tocontrol and/or monitor liquid dispense actuation.

It is, therefore, an object of the present invention to provide aninnovative dispensing device that overcomes the inconveniences andlimitations presented by the prior art documents.

SUMMARY OF THE INVENTION

Thus, the present invention concerns a dispensing device fulfillingthese objectives efficiently, which may be obtained in a relativelysimple and inexpensive manner, as defined in the appended claims. Thedevice is further capable of indirectly triggering and monitoringitself.

Thus, in accordance with a first embodiment of the present invention, aself-sensing dispensing device is provided that includes: power supplymeans (4, 24, 34); a liquid dispensing element (9, 29, 39) comprising anactuator (11, 211, 311) and a dispensing aperture (10, 210, 310) throughwhich liquid is to be dispensed by activation of the actuator;electronic control means (6, 26, 33) operable to control the actuator;liquid supply means (8, 18, 28) for connecting with a liquid reservoir(1, 21, 31) to supply liquid from the reservoir to the liquid dispensingelement; valving means (7, 27, 37, 47) for allowing or blocking liquidto flow from the reservoir through the liquid supply means to the liquiddispensing element, wherein the actuator is operable to execute initself at least a dispensing function and a detecting function, thedetecting function detecting at least characteristics external to theself-sensing dispensing device and causing the actuator to generate acommand signal, and wherein the electronic control means is operable tocontrol the valving means and the actuator based on the reception of thecommand signal. In accordance with a second embodiment of the invention,the first embodiment is modified so that the electronic control means isoperable to open and/or close the valving means based on the commandsignal. In accordance with a third embodiment of the invention, thesecond embodiment is further modified so that the electronic controlmeans is operable to turn on and off the self-sensing dispensing devicebased on the command signal.

In accordance with a fourth embodiment of the invention, the firstembodiment, the second embodiment and the third embodiment are furthermodified so that the electronic control means is operable to analyze atime-frequency response of the command signal, the result of theanalysis allowing to trigger the valving means. In accordance with afifth embodiment of the invention, the fourth embodiment is furthermodified so that the electronic control means comprises memory means forstoring results of the analysis for self-learning purposes.

In accordance with a sixth embodiment of the invention, a self-sensingdispensing device is provided that includes: power supply means (4); aliquid dispensing element (9) comprising an actuator (11, 211, 311) anda dispensing aperture (10) through which liquid is to be dispensed byactivation of the actuator; electronic control means (6) operable tocontrol the actuator; liquid supply means (8′) for connecting with aliquid reservoir (1) to supply liquid from the reservoir to the liquiddispensing element, wherein the actuator (10) is operable to execute initself at least a dispensing function and a detecting function, thedetecting function detecting at least characteristics external to theself-sensing dispensing device and causing the actuator to generate acommand signal, and wherein the electronic control means is operable tocontrol the actuator based on the reception of the command signal. Inaccordance with a seventh embodiment of the present invention, the firstembodiment, the second embodiment, the third embodiment, the fourthembodiment, the fifth embodiment and the sixth embodiment are modifiedso that the actuator is a piezoelectric actuator. In accordance with aneighth embodiment of the present invention, the first embodiment, thesecond embodiment, the third embodiment, the fourth embodiment, thefifth embodiment, the sixth embodiment and the seventh embodiment aremodified so that the actuator is an electromagnetic actuator.

In accordance with a ninth embodiment of the present invention, a showerapparatus is provided that includes: a showerhead (13); and a water flowdetector, wherein the water flow detector consists of a self-sensingdispensing device according to the seventh embodiment. In accordancewith a tenth embodiment of the present invention, a respiratorytreatment device is provided that includes: a self-sensing dispensingdevice according to the seventh embodiment; a mouthpiece; and a fluidicinterface, wherein the electronic control means and the piezoelectricactuator are arranged to detect a breathing pattern of a user throughthe mouthpiece.

In accordance with an eleventh embodiment of the invention, a liquiddispenser is provided that includes: a self-sensing dispensing deviceaccording to the seventh embodiment, wherein the dispensing element hasat least one outlet for dispensing the liquid as a flow, and theelectronic control means and the piezoelectric actuator are arranged todetect presence or movement of an object in the proximity of thepiezoelectric actuator. In accordance with a twelfth embodiment of theinvention, a liquid dispenser is provided that includes: a self-sensingdispensing device according to a sixth embodiment of the presentinvention, wherein the dispensing element has at least one outlet fordispensing the liquid as a flow, and the electronic control means andthe electromagnetic actuator are arranged to detect presence or movementof an object in the proximity of the electromagnetic actuator. Inaccordance with a thirteenth embodiment of the invention, a householdappliance is provided that includes a self-sensing dispensing deviceaccording to the sixth embodiment of the present invention.

Thanks to the features of the self-sensing dispensing device accordingto the present invention, it is possible to reliably control theoperation of the liquid dispensing device, and this without requiringany separate sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the self-sensing dispensing deviceaccording to the present invention will become clear from reading thefollowing description, which is given solely by way of a non-limitativeexample thereby referring to the attached drawings in which:

FIG. 1 a shows a first example of a self-sensing piezoelectricdispensing device in a first illustrative embodiment according to thepresent invention used in a water flow detector of a shower apparatus;

FIG. 1 b shows a second example of a self-sensing piezoelectricdispensing device in the first illustrative embodiment;

FIG. 1 b 1 shows an example of a priming system for a self-sensingpiezoelectric dispensing device in the first illustrative embodiment;

FIG. 1 c shows a third example of a self-sensing piezoelectricdispensing device in the first illustrative embodiment;

FIGS. 1 d and 1 e show examples of signals used in a water flowdetection in the first illustrative embodiment;

FIG. 2 a shows an example of a self-sensing piezoelectric dispensingdevice in a second illustrative embodiment according to the presentinvention used in an inhaler or nebulizer;

FIGS. 2 b and 2 c show a time domain response and a frequency responsefor a detected inhalation airflow of a person using a self-sensingpiezoelectric dispensing device in the second illustrative embodiment;

FIGS. 2 d and 2 e show in analogy the detected exhalation flow of theself-sensing piezoelectric dispensing device in the second illustrativeembodiment;

FIG. 3 a shows a first example of a self-sensing piezoelectricdispensing device in a third illustrative embodiment according to thepresent invention used in a liquid dispenser with a hand proximitydetection;

FIG. 3 b shows a second example of a self-sensing electromagneticdispensing device in the third illustrative embodiment; and

FIGS. 3 c and 3 d show examples of signals used in the hand proximitydetection in the third illustrative embodiment.

DETAILED DESCRIPTION OF THE INVENTION

An example of preferred illustrative embodiments will now be describedwhile referring to the figures. Generally, the self-sensing dispensingdevice according to the present invention is used to control theoperation of an actuator in a liquid dispensing device.

First Illustrative Embodiment

In the first illustrative embodiment, a self-sensing piezoelectricdispensing device is used as a water flow detector arranged close to ashowerhead of a shower apparatus. By detecting a flow of water, acleaning, disinfecting or fragrancing formulation, or the like, may bedispensed from the self-sensing piezoelectric dispensing device. Thismay be done. for example, by way of a spray of droplets, i.e. in such acase the dispensing device is an atomizer or liquid droplet spraydevice.

Shower cleaning devices are known as such. For example, the documentU.S. Pat. No. 6,820,821 discloses an automated sprayer for spraying thewalls of a bath and shower enclosure with a cleanser. The sprayer has ahousing that can be mounted inside the shower enclosure. A tube extendsdownwardly along a longitudinal axis through which the cleanser canpass. A motorized head disposed beneath the tube can be rotated aboutthe axis for metering cleanser from the bottle and spraying cleanseroutward. The sprayer includes a motion sensor to prevent spraying ifsomeone is present in the shower.

Clearly such a device requires a separate sensor to allow for triggeringof the desired operation (spraying of cleaner) making the system morevulnerable and more expensive.

Thanks to the features of the present invention, a separate sensor canbe avoided, as it is the piezoelectric actuator itself that functions asa sensor. Therefore, reliability can be improved, as there are fewerparts prone to malfunctioning.

A first example of the first illustrative embodiment is shown in FIG. 1a where a pressurized cleaner tank 1 is provided for containing aliquid. A venting hole 2 is advantageously provided with a hydrophobicmembrane to ensure correct priming by tank over-pressuring and also toensure correct emptying of the tank.

Alternatively, as shown in FIG. 1 b 1, instead of a hydrophobicmembrane, a liquid feed conduit 81 having a cut-out section acting as aventing hole 2 can be used to pressurize the liquid and to vent the tankand feed the liquid to an inlet channel 8. As shown in this Figure,first this liquid feed conduit 81 is ready to be inserted into the tank(A). At this stage, the pressure P_(int) in tank 1 is equal to theatmospheric pressure P_(atm). Next, it enters the tank (B), so that theinternal pressure P_(int) becomes greater than P_(atm). Finally itarrives at the bottom of the tank such that the venting hole allows forrelease of air (C) so that P_(int) equals again P_(atm).

Tank 1 is placed in a housing 3 fitted to a shower apparatus having ashowerhead 13. Housing 3 further contains a battery 4 and appropriateelectronic control means 6 for activating and deactivating a dispensingelement, here a liquid spray head 9. Liquid spray head 9 is mounted on asupport, for example, a wall 12 in the vicinity of showerhead 13. Liquidspray head 9 comprises a piezoelectric actuator 11 and an aperture plateor nozzle head 10 having one or more outlet nozzles through which theliquid cleaning solution is expelled as a spray of droplets, in a mannerwell known to a person of the art. An inlet channel 8 is provided tosupply liquid from tank 1 to spray head 9. Inlet channel 8 may bemounted to support 12 by way of a clip 5. Access from tank 1 to sprayhead 9, through inlet channel 8, may be controlled by valving means, forexample an electro-valve 7, suitably arranged between the tank and thespray head, and controlled by electronic control means 6.

As the person skilled in the art will readily recognize there can be oneor more tanks and one or more liquids. Electrovalve 7 can be a one wayvalve or a multi-way valve. There can be one or several liquid sprayheads. Also, the tank arrangement and the liquid spray arrangement maybe side by side on a surface instead of on different sides of a wallsuch as shown in FIGS. 1 a, 1 b and 1 c.

As such, any liquid supplied to spray head 9 is put into vibration bypiezoelectric actuator 11 so that ultrasonic energy thus created acts onliquid in spray head 9 to cause it to be ejected as a spray of dropletsthrough the nozzle(s) 10, in a manner known to the skilled person.

Indeed, the piezoelectric actuator is operable to execute at least adispensing function and a detecting function. The dispensing functionmay be triggered by an electronic control signal from electronic controlmeans 6 for vibrating the piezoelectric actuator, whereby the ultrasonicenergy is transmitted to the liquid so as to allow for vibrationthereof, thereby resulting in the dispensing of the liquid from thedispensing element through the nozzle(s) 10. The detecting function isused to detect at least characteristics external to the dispensingdevice and results in a perturbation of the piezoelectric actuator. Thisperturbation generates an electronic signal, which may be detected byelectronic control means 6, and thus may constitute a command signal ofelectronic control means 6 for controlling valving means 7 and sprayhead 9.

As can be understood from the above description, according to thepresent invention, piezoelectric actuator 11 not only allows liquid tobe dispensed, but it also allows to control when, how and which liquid(when using more than one tank) is to be dispensed. In fact, by usingthe principle of piezoelectricity not only to convert electricity tomechanical movement, but also to convert mechanical perturbations backto electricity, the piezoelectric actuator 11 can be used to detectexternal characteristics, in this case water flow of the shower, as suchwater flow creates combined sonic and ultrasonic pressure waves in theproximity of the shower apparatus, which causes perturbation that can bepicked up by piezoelectric actuator 11, thus allowing detection of thewater flow. By appropriate analysis of the electrical signals resultingfrom the water flow pressure waves through electronics means 6, it ispossible to determine when water flow starts and stops. It is then alsopossible to control, once the water flow is detected as started,electro-valve 7 so that liquid may be provided from tank 1 to spray head9 and thus be ejected by self-sensing actuator 11. This control can becarried out by the electronic control means 6, triggered by theself-sensing piezoelectric actuator 11. Thus, a shower apparatus havingsuch a water flow detector can then automatically trigger release of acleaning, fragrancing, or disinfecting substance.

The analysis of the electrical signals resulting from the waterflow-generated pressure waves will be explained in more detail withrespect to FIGS. 1 c and 1 d. As can be seen in FIG. 1 c, the start andstop of the water flow can be readily detected as the pressure wavesdetected by piezoelectric actuator 11 increase sharply when water flowstarts, and decrease rapidly when the water flow stops. Using thissignal, it is possible to apply a threshold detection additional to theabove analysis, as shown for example in FIG. 1 d, above which a waterflow is considered to be in progress. Thus, the start and stop of awater flow can be readily detected by the self-sensing spray head 9.

The piezo-generated electric signal undergoes appropriate filtering inorder to reliably isolate the water flow-originated signal fromeverything else picked-up (i.e. background noise).

Of course, a skilled person can readily conceive other applications, forexample, in the case of 2 tanks and 2 different liquids, and, forexample, a fragrancing and a disinfecting liquid, and the self-sensingspray head 9 and the electronic control means 6 may be arranged to allowspraying of the fragrancing liquid during the showering process andspraying the disinfecting liquid some predetermined time after theshowering process. It will also be evident to the skilled person thatthe applications may not be not limited to showers, but that there maybe other devices that use the same self-sensing principle, includingapplications in household appliances, like laundry dryers, vacuumcleaners, cleaning robots, and the like.

A second example of the first illustrative embodiment is shown in FIG. 1b where an arrangement is shown that is rather similar to the one in thefirst example. Same elements are referred to by the same referencenumerals. In this second example, housing 3 is arranged above tank 1,and thus inlet channel 8 extends into the tank to allow the liquidsolution to be drawn out towards spray head 9. As can be understood fromthis shown configuration, compared to the upside-down configuration ofthe first example, the configuration of the second example avoidspossible leakage of residual liquid after removing tank 1.

A third example of the first illustrative embodiment is shown in FIG. 1c where a rather similar arrangement is shown as in the second example.Same elements are referred to by same reference numerals. In this thirdexample, housing 3 is thus also arranged above tank 1. Here, the inletchannel is formed of two parts, a first part 7′, which is in thisexample a wick contained in tank 1, and a second part 8′, which may alsobe a wick, or may be a capillary channel for transporting the liquidprovided from tank 1 by way of wick 7′ to spray head 9. This exampledoes not use an electro-valve, so that the liquid transfer from tank 1to spray head 9 is performed by capillarity (i.e., capillary action).

In order to avoid leakage due to the absence of valving means, sprayhead 9 is positioned such that the hydrostatic pressure at spray head 9is higher than the hydrostatic pressure in tank 1.

As can be understood from the above, in all examples of this firstillustrative embodiment, any release of liquid from tank 1, and thusfrom the dispensing device is controlled by signals provided by theself-sensing piezoelectric actuator.

Second Illustrative Embodiment

In the second illustrative embodiment, the self-sensing piezoelectricdispensing device is used as a breathing pattern detector in arespiratory treatment device allowing to trigger the release of asubstance.

Respiratory treatment devices are generally known as inhalers ornebulizers for delivering active substances to a user by means of his orher respiratory system. It may be used, for example, for the controlledadministration of drugs or for a variety of treatments includingtherapies and general wellness oriented applications. The respiratorytreatment device delivers the substance, which may be in the form of aliquid or gel, as a dispersion of atomized droplets. Preferably, such adevice is small in size and battery operated so that the user may carryand use it in a discreet manner. Such devices are well known as such,see for example the documents EP 923 957 or U.S. Pat. No. 6,405,934B1,both in the name of the present Applicant.

FIG. 2 a shows an example of a respiratory treatment device comprising aself-sensing piezoelectric spray head 29 according to the presentinvention. A reservoir 21 is provided attached to a housing 22.Reservoir 21 may contain a substance that is to be expelled as a sprayof droplets from the inhaler into the mouth of a person operating therespiratory treatment device. The respiratory treatment device furthercomprises a mouthpiece 26 and a fluidic interface 25 allowing thesubstance from reservoir 21 to arrive at the mouthpiece 26. Mouthpiece26 contains a liquid dispensing element, i.e., spray head 29, comprisinga piezoelectric actuator 211 and a nozzle head 210 having one or moreoutlet nozzles through which the substance is expelled as a spray ofdroplets. This spray head may, of course, be similar to the one of thefirst illustrative embodiment. In a similar manner to the firstillustrative embodiment, an inlet channel 28 and valving means, such asan electro-valve 27, may be provided for supplying the substance fromreservoir 21 to spray head 29.

Housing 22 comprises electronic control means 23 and a power source,such as battery 24, for supplying power to the electronic control means23 and to the piezoelectric actuator 211. Again, these parts may beidentical to those described in the first illustrative embodiment.

According to the second illustrative embodiment, piezoelectric actuator211 again converts mechanical perturbations to electricity, but nowapplies the principle to the detection of the inhalation and exhalationpattern of a person using the respiratory treatment device. Indeed, whenputting the mouthpiece into the mouth, a person will inhale and exhale.This inhalation/exhalation causes perturbations of the piezoelectricactuator so that the inhalation and exhalation airflows of the personcan be detected. By appropriate analysis of these inhalation andexhalation sequences, the substance to be administered can be expelledas a spray by the self-sensing spray head 29 at the appropriate time toallow for an efficient treatment, i.e., while the person is actuallyinhaling, and not exhaling.

FIGS. 2 b and 2 c show the time response and the frequency response fora detected inhalation of a person. By using an appropriatetime-frequency analysis, the beginning and the end of the inhalationprocess can be clearly detected. By using, for example, a thresholddetection additional to the above analysis, the electronic control means23 can trigger electro-valve 27 to allow substance to be supplied tospray head 29 for spraying into the person's mouth after detection ofthe beginning of the inhalation process and then electro-valve 27 canagain be closed to block further access of substance to the spray head,once the end of the inhalation process is detected.

FIGS. 2 d and 2 e show, in analogy, the exhalation process detected bypiezoelectric actuator 211. Thus, this process is carried out in ananalogous manner to the one described above for the inhalation process.As such, triggering of the spray device may be prevented duringexhalation.

By using these detection methods, in accordance with the presentinvention the inhalation can be differentiated from the exhalation.Indeed, as can be seen from FIGS. 2 b to 2 d, the inhalation andexhalation can be differentiated by an appropriate time-frequencyanalysis.

As can be understood from the above, in this second illustrativeembodiment, again the release of a substance from reservoir 21, and thusfrom the dispensing device is controlled by signals provided by theself-sensing piezoelectric actuator 211.

Third Illustrative Embodiment

FIG. 3 a shows a first example of a self-sensing piezoelectricdispensing device in a third illustrative embodiment according to thepresent invention used in a liquid dispenser.

In this illustrative embodiment, the piezoelectric actuator 311 is alsoused as a proximity sensor, for example, for detecting the presence of ahand passing in front of the dispenser, thus allowing control of releaseof the substance to be dispensed. As an example, the liquid dispensermay release soap from a spout onto a hand.

The dispensing device is again rather similar to that of the first andsecond illustrative embodiments. Thus, a housing 32 is providedcomprising a reservoir 31 for containing liquid to be dispensed. Alsoprovided are a battery 34 and electronic control means 33 forcontrolling the release of liquid, by way of signals sent by thepiezoelectric actuator, similar to the functioning in theabove-described illustrative embodiments.

Thus, here too, any release of liquid from reservoir 31, and thus fromthe dispensing device is controlled by signals provided by thepiezoelectric actuator 311.

Indeed, as can be seen from FIG. 3 a, again inlet means are provided forproviding a fluidic connection between reservoir 31 and a dispensingelement, here dispensing head 39 by way of valving means, such as anelectro-valve 37. Dispensing head 39 comprises a dispensing aperture310, for example, a spout, having one or more nozzles through which theliquid is to be dispensed. A piezoelectric actuator 311 is also providedin the dispensing head to allow control of electro-valve 37, bydetection of the proximity of a hand, and thus of the release of liquidfrom the reservoir, and ultimately from the dispensing device.

FIG. 3 b shows a second example of a self-sensing dispensing device inthe third illustrative embodiment. It merely differs from the abovefirst example in that the self-sensing dispensing device comprises anelectromagnetic dispenser instead of a piezoelectric dispenser. Theother parts are identical to those of FIG. 3 a and are identified by thesame reference numerals. Thus, an electromagnetic actuator 47 is usedinstead of a piezoelectric actuator. The windings of thiselectromagnetic actuator may be used, for example, to detectperturbations in an electromagnetic field caused by the presence ormovement of a hand in its proximity.

In this illustrative embodiment, and indeed in all other embodimentstoo, the dispenser may be arranged to emit an appropriate electricalsignal to detect reflection thereof, by way of analysis of the returnsignal. As such, any movement, object or presence below the actuator canbe detected. Such analysis of a return signal is well known as such to aperson skilled in the art. Thus, in the first example of the thirdillustrative embodiment where the self-sensing dispensing device may be,for example, a soap dispenser, when a hand arrives in the proximity ofthe dispenser, its presence is detected by the return signal bouncingoff the hand. This return signal is then analyzed by the electroniccontrol means 33 in order to control the valving means, so as to allowliquid to flow from reservoir 31 to dispensing head 39, and ultimatelyto leave the dispensing device onto the hand below it. Once the hand isremoved, the return signal will change so that this can also bedetected, therefore allowing the dispensing operation to stop by closingthe valving means.

FIGS. 3 c and 3 d shows examples of signals used in a hand proximitydetection in the second example of the third illustrative embodiment.

As can be seen, the proximity and the absence of proximity can bereadily detected by appropriate time-frequency analysis of the signalsshown in FIG. 3 c and FIG. 3 d.

As can be understood from the description of the above threeillustrative embodiments, a smart dispensing device may be obtained byusing a self-sensing dispenser.

Actuation can be triggered by an acoustic pressure wave, noise, abreathing pattern, presence detection, or by motion detection.

Additional advantages of the self-sensing dispensing device according tothe present invention concern the fact that sensing and dispensingactions are carried out by the same component. In conventional devices,a dispensing device could continue to dispense even when the separatesensor has failed, thus leading to waste of the dispensed liquid. For aninhaler, this could even be dangerous to a patient, as the inhaled dosemay be much higher than permitted.

Clearly, a cheaper device may also be obtained, as no separate sensorneeds to be provided, connected and calibrated.

Furthermore, the dispensing device according to the present inventionmay be provided with self-learning technology. For example, theelectronic control means may be provided with a memory for storingdetection results and to allow for a self-calibration, by comparing withpreviously stored detection results. For instance, the electroniccontrol means may analyze the envelope of the command signal generatedby the actuator by comparing it with pre-stored signals, the result ofthis comparison allowing to trigger the actuation means.

Moreover, the present self-sensing piezoelectric dispenser may evendetect clogging, as this leads to modification of the electro-mechanicalcharacteristic of the self-sensing piezoelectric dispenser.

Also, an empty detection in the dispenser can be performed in thismanner, so the piezoelectric actuator can be stopped.

Having described now the preferred embodiments of this invention, itwill be apparent to one of skill in the art that other embodimentsincorporating its concept may be used. It is felt, therefore, that thisinvention should not be limited to the disclosed illustrativeembodiments, but rather should be limited only by the scope of theappended claims.

1. A self-sensing dispensing device comprising: (a); (a) a liquiddispensing element comprising an actuator and a dispensing aperturethrough which liquid is to be dispensed by activation of the actuator;(b) power supply means operably connected to power the actuator; (c)electronic control means operable to control the actuator; (d) liquidsupply means for connecting with a liquid reservoir to supply liquidfrom the reservoir to the liquid dispensing element; valving means forallowing or blocking liquid flow from the reservoir through the liquidsupply means to the liquid dispensing element, wherein the actuator isoperable to execute in itself at least a dispensing function and adetecting function, wherein the detecting function detects at leastcharacteristics external to the self-sensing dispensing device andcauses the actuator to generate a command signal, and wherein theelectronic control means is operable to control the valving means andthe actuator based on the reception of the command signal.
 2. Aself-sensing dispensing device according to claim 1, wherein saidelectronic control means is operable to open, or close, or to open andclose, said valving means based on said command signal.
 3. Aself-sensing dispensing device according to claim 2, wherein saidelectronic control means is operable to turn on and off saidself-sensing dispensing device based on said command signal.
 4. Aself-sensing dispensing device according to claim 1, wherein saidelectronic control means is operable to analyze a time-frequencyresponse of said command signal, wherein the result of said analysisallows triggering of said valving means.
 5. A self-sensing dispensingdevice according to claim 4, wherein said electronic control meanscomprises memory means for storing results of said analysis forself-learning purposes.
 6. A self-sensing dispensing device comprising:(a) a liquid dispensing element comprising an actuator and a dispensingaperture through which liquid is to be dispensed by activation of theactuator; (b) power supply means operably connected to power theactuator; (c) electronic control means operable to control saidactuator; (d) liquid supply means connecting with a liquid reservoir tosupply liquid from the reservoir to the liquid dispensing element;wherein the actuator is operable to execute in itself at least adispensing function and a detecting function, wherein the detectingfunction detects at least characteristics external to the self-sensingdispensing device and causes the actuator to generate a command signal,and wherein the electronic control means is operable to control theactuator based on reception of the command signal.
 7. A self-sensingdispensing device according to claim 1, wherein said actuator is apiezoelectric actuator.
 8. A self-sensing dispensing device according toclaim 1, wherein said actuator is an electromagnetic actuator.
 9. Ashower apparatus comprising: a showerhead; and a water flow detector,wherein said water flow detector consists of a self-sensing dispensingdevice as defined in claim
 7. 10. A respiratory treatment devicecomprising: a self-sensing dispensing device as defined in claim 7; amouthpiece; and a fluidic interface, wherein the electronic controlmeans and the piezoelectric actuator are arranged to detect a breathingpattern of a user through the mouthpiece.
 11. A liquid dispensercomprising: a self-sensing dispensing device as defined in claim 7,wherein said dispensing element has at least one outlet for dispensingsaid liquid as a flow, and said electronic control means and saidpiezoelectric actuator are arranged to detect presence or movement of anobject in a proximity of said piezoelectric actuator.
 12. A liquiddispenser comprising: a self-sensing dispensing device as defined inclaim 7, wherein said dispensing element has at least one outlet fordispensing said liquid as a flow, and said electronic control means andsaid electromagnetic actuator are arranged to detect presence ormovement of an object in a proximity of said electromagnetic actuator.13. A household appliance comprising a self-sensing dispensing device asdefined in claim
 6. 14. A self-sensing dispensing device according toclaim 2, wherein said electronic control means is operable to analyze atime-frequency response of said command signal, wherein the result ofsaid analysis allows triggering of said valving means.
 15. Aself-sensing dispensing device according to claim 3, wherein saidelectronic control means is operable to analyze a time-frequencyresponse of said command signal, wherein the result of said analysisallows triggering of said valving means.